The first step to setting up a guitars action is to determine the neck relief and make a truss rod adjustment if necessary, the first step, not the last, to check the relief, put the guitar in your normal playing position, place a capo across the first fret position or just fret a string with your finger and hold it down, with your other hand press down the same string at the 15th fret, now look very closely at the 7-8th fret area, there should be some clearence between the top of the fret and the bottom of the string, a rough estimate would be 1/2 the thickness of the string you are fretting, more than that and you might need to lessen the relief, less to 0 clearence, and you will probaly need to add some relief, you have to have some relief in the neck or it will buzz on the frets. The perfect neck is not straight or flat, from the 2nd fret to the 12-15th fret you have to have a slight bow toward the strings, from the 15th on up the fret tops/fretboard should gradually and slightly "fall away" from the strings, this is why some many guitars start fretting out and buzzing above the 15th fret. I don't encourage anyone to work on their own guitar, but a person that has the desire, patience, tools and stubborn hard headed personality and will do it anyhow I will advise if I can........